HPLC analysis of ballpoint pen inks stored at different light conditions

A method for comparison of ink entries on documents stored in different lig ht conditions is presented. Various blue inks were exposed to light, both d aylight and artificial light from fluorescent tubes. Inks were then extract ed from the document and analyzed by HPLC thigh performance liquid chromaro graphy). Significant changes in composition were noted on exposure to light . These changes were followed by using ternary diagrams constructed for dye s generally present in blue-colored inks-Crystal Violet, Methyl Violet, and Tetramethyl Para Rosaniline. Also, the amount of the various compounds for med by decomposition of these dyes on exposure to light was measured and em ployed for comparison of inks. An example of the use of the proposed method in casework is given.